PIC12F615 ADC interrupt exemple

pic12f615_adc_interrupt.c

#include "xc.h"
#include "config.h"

#define _XTAL_FREQ 4000000

unsigned short pot = 0;

void interrupt isr() {

    // Disable GIE (best practice?)
    INTCONbits.GIE = 0;

    // Handle ADC conversion end interrupt
    if(PIR1bits.ADIF == 1) {
        pot = (ADRESH<<8) + ADRESL;
        PORTAbits.GP5 = (pot < 512) ? 1 : 0;
        PIR1bits.ADIF = 0;
    }

    // Handle Rising edge interrupt
    if(INTCONbits.INTF == 1) {
        PORTAbits.GP0 =! PORTAbits.GP0;
        INTCONbits.INTF = 0;
    }

    // Enable GIE (best practice?)
    INTCONbits.GIE = 1;
}

void main(void) {

    /*Configure peripheral*/
    //Configure GP2
    TRISAbits.TRISIO2 = 1;  // GP2 as input
    ANSELbits.AN2 = 0;      // GP2 not analog

    //Configure GP5
    TRISAbits.TRISIO5 = 0;  // GP5 as output
    PORTAbits.GPIO5 = 0;    // GP5 set low

    //Configure GP0 > PWM
    ANSELbits.AN0 = 0;
    TRISAbits.TRISIO0 = 0;  // GP0 as output
    PORTAbits.GPIO0 = 1;    // GP0 set high

    //Configure GP4/AN3/CHS2 > ADC
    // > port
    TRISAbits.TRISIO4 = 1;  // GP4 as input
    ANSELbits.ADCS0 = 1;
    ANSELbits.AN3 = 1;      // GP4 as analog
    // > channel
    ADCON0bits.CHS = 0b011; // select ADC channel 2
    // > left
    ADCON0bits.ADFM = 1;
    // > voltage reference
    ADCON0bits.VCFG = 0;    // VDD as Vref
    // > clock source
    ANSELbits.ADCS0 = 0b100;// Set clock source as FOSC/2
    // > enable ADC module
    ADCON0bits.ADON = 1;    // enable ADC

    /*Configure interrupts*/
    //Button
    //INTCONbits.GIE = 1;         //enable global interrupt
    INTCONbits.PEIE  =1;
    INTCONbits.INTE = 1;        //enable external interrupt on GP2
    OPTION_REGbits.INTEDG = 1;  //enable interrupt on rising edge on GP2
    INTCONbits.INTF = 0;        //clear interrupt flag
    //ADC
    PIE1bits.ADIE = 1;          // enable ADC interrupt
    PIR1bits.ADIF = 0;          // clear ADC interrupt flag

    ei();

    while(1) {
        ADCON0bits.GO = 1;
        __delay_ms(500);
    }
}